/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following disclaimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The groups "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their group, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: Bans.java,v 1.3 2006/06/12 20:45:22 nano Exp $
*/

package net.jxta.myjxta.directive.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import net.jxta.myjxta.dialog.DialogMessage;

/**
 *
 * @version $Id: Bans.java,v 1.3 2006/06/12 20:45:22 nano Exp $
 *
 * @author james todd [gonzo at jxta dot org]
 */

public class Bans {

    private static Bans instance = null;

    private List<String> bans = null;

    /**
     * Returns the handle to this singleton instance.
     */
    public static synchronized Bans getInstance() {
        if (instance == null) {
            instance = new Bans();
        }

        return instance;
    }

    /**
     * Returns the <code>List</code> of peer ids that have been banned in this session.
     */
    public List getBans() {
        return this.bans != null ?
               this.bans : Collections.EMPTY_LIST;
    }

    /**
     * Returns true if the originator of the supplied DialogMessage is banned, and false otherwise.
     */
    public boolean isBanned (DialogMessage msg) {
        if (msg == null) {
            return false;
        }

        return isBanned(msg.getOriginator());
    }

    /**
     * Returns true if the supplied peer id is banned, and false otherwise.
     */
    public boolean isBanned (String peer) {
        if (peer == null) {
            return false;
        }

        return getBans().contains(peer);
    }

    /**
     * Adds the supplied peer to the list of banned peers.
     */
    public void addBan(String peer) {
        peer = peer != null ? peer.trim() : peer;

        if (peer != null) {
            if (this.bans == null) {
                this.bans = new ArrayList<String>();
            }

            if (! this.bans.contains(peer)) {
                this.bans.add(peer);
            }
        }
    }

    /**
     * Adds the supplied peer <code>List</code> to the list of banned peers.
     * 
     * @param bans A <code>List</code> of <code>Strings</code>.  Each element in the list is a peer id.
     */
    public void addBans(List<String> bans) {
        this.bans.addAll(bans);
    }

    /**
     * Removes the supplied peer from the list of banned peers.
     */
    public void removeBan(String peer) {
        peer = peer != null ? peer.trim() : null;

        if (peer != null &&
            this.bans != null) {
            this.bans.remove(peer);

            if (this.bans.size() == 0) {
                this.bans = null;
            }
        }
    }

    /**
     * Removes the supplied peer <code>List</code> from the list of banned peers.
     * 
     * @param bans A <code>List</code> of <code>Strings</code>.  Each element in the list is a peer id.
     */
    public void removeBans(List bans) {
        this.bans.removeAll(bans);
    }

    /**
     * Removes all peers <code>List</code> from the list of banned peers.
     */
    public synchronized void clearBans() {
        if (this.bans != null) {
            this.bans.clear();
            this.bans = null;
        }
    }

    /**
     * Limits the instantiation of this class.
     */
    protected Bans() {
        super();
    }
}
